September 26, 2013

The big issue: groundwater

academic.evergreen.edu

By the time I got to the Land Court on Monday there was a buzz about Lock the Gate's report on groundwater guzzling by the proposed mega coal mines of the Galiliee Basin. Groundwater is a very big issue there: it is the bottom line of viability for graziers in Central Queensland.

The six-month study, in consultation with a former Queensland government water planning manager, Tom Crowthers, found that the majority of water bores in the mine lease areas would be unworkable by the time the mines are operational. The coal seams lie beneath important aquifers that would have to be drained (dewatered) in order to access the coal. In addition, vast quantities of water would be needed to wash the coal and suppress dust. The study used information from the Environmental Impact Statements of five of the proposed mines to extrapolate figures for the other four.

Draining the Life-blood: Groundwater Impacts of Coal Mining in the Galilee Basin* predicts that 1,345 billion litres of water would have to be drained from the Basin by all nine mines** before they can extract the coal. This is the equivalent of two and a half Syd Harbours. (We know how much people here like to compare extremely large quantities of water with the volume of Australia's most celebrated harbour, although I would imagine few people have any idea just how much water that is.) Another 50-70 billion litres a year would be used by the Galilee mines for washing and other purposes.

The importance of the Galilee's groundwater for its towns and pastoralists cannot be overstated. A number of aquifers are at risk according to Lock the Gate. Surface water will not escape impact: water courses will be diverted, for example, for additional mining purposes. The Independent Expert Scientific Committee on Coal Seam Gas and Large Coal Mining Development, established by the Federal government in 2012 in an amendment to the Environment Protection and Biodiversity Conservation Act, have gone further, and suggested that the dewatering of the Galilee Basin will have an impact on the aquifers of the Great Artesian Basin. They also expressed concern about the inadequacy of hydrogeological data provided for groundwater modelling parameters by Hancock Coal for their Alpha mine, the first of the megas to obtain Federal approval. The IESC and many experts believe that cumulative impact studies are essential before mining can proceed.

In the Land Court over the last few days, two groundwater experts have taken the stand and referenced groundwater modelling by consultants, audits by other consultants, and joint expert conferences and reports. There appeared to me to be a distinct lack of consensus, however, about the parameters for the modelling in question, and a degree of uncertainty about predictions that at times bordered on lack of confidence.

As one of the graziers opposing the Alpha mine approval pointed out to me: if Hancock Coal is so sure of its claim that bores on stations adjoining the mine lease area will not be affected by drawdown, why won't they sign make-good agreements that give the farmers firm assurances of their commitment to the maintenance of water supplies. Those agreements have stalled.

** the nine mine proposals include more than 34 opencast pits and 15 underground mines along a 270-kilometre north south strike and will produce more than 300 million tonnes of coal a year when they are all fully operational